def guess(number):
    i=0
    original_number=number
    while number!=1:
        if number%2==0:
            number=number/2
        else:
            number=number*3+1
        i+=1
    print(f"{original_number}经过{i}次变换后回到1")
num=int(input("请输入一个大于1的正整数："))
guess(num)